JavaScript Beautifier

What this tool does

JavaScript Beautifier reformats minified or inconsistently indented JavaScript into clean, properly structured, readable code with an adjustable indent size, using the js-beautify library entirely in your browser.

Minified JavaScript, from a production build’s output or someone else’s minified script, is nearly impossible to read or debug line by line until it’s reformatted with proper structure and indentation.

This tool rebuilds readable, properly structured code at your chosen indent width, using the same formatting engine behind many code editors, entirely inside your browser.

How to use JavaScript Beautifier

1. Paste your minified or messy JavaScript.
2. Adjust the indent size if you prefer something other than 2 spaces.
3. Copy or download the formatted output.
4. Re-run it any time you paste in a different snippet.

Tips for better results

• Beautifying doesn’t change what the code actually does, only its formatting (whitespace, line breaks, indentation), execution behaviour is identical before and after.
• Beautified (unminified) code doesn’t recover original variable names that mangling may have replaced, it formats the code structurally but can’t guess back meaningful names that were already shortened during minification.
• This is the reverse operation of the JavaScript Minifier tool, useful for inspecting a production build’s bundled output or debugging an issue in a minified third-party script.
• For genuinely complex minified code (deeply nested, heavily optimised), beautified output is still structurally readable even without original variable names, a real improvement over a single unreadable line.

Common use cases

• Making a minified production JavaScript bundle readable again for debugging.
• Inspecting a third-party minified script’s logic for troubleshooting or learning purposes.
• Reformatting someone else’s inconsistently indented JavaScript to match your own style.
• Converting a compact one-line script into properly structured, readable multi-line code.

Common mistakes to avoid

• Expecting beautifying to recover original, meaningful variable names after mangling; it only restores structural formatting (indentation, line breaks), the renamed variables stay renamed, since that information was already discarded during minification.
• Expecting beautifying to change the code’s actual execution behaviour; it only reformats whitespace and structure, runtime behaviour is completely identical before and after.
• Using a different indent size across files in the same project; standardise on 2 or 4 spaces for the cleanest, most consistent result codebase-wide.